Asked what support his government might give to the workers, Mr Baird pointed to a payroll tax rebate on offer to companies that employ staff laid off in mass redundancies.

Arrium said its volumes in its Australian mining materials business during the second half of the 2013/14 financial year were expected to be down about 45 per cent on the same period a year earlier.

As a result, the business was expected to suffer a hit to underlying earnings in the second half of between $15 million and $17 million.

Arrium's steel and recycling business was also being impacted by enduring weakness in the domestic and offshore steel markets, although Mr Roberts said there had been a modest improvement in the Australian construction market.

Sales in the second half of the financial year are expected to be flat, compared to the first half, due to delays on major projects such as the Pacific Highway in NSW and Sydney's Barangaroo development.

Sales are expected to lift in the 2014/15 year, Mr Roberts said.

The company also has iron ore mining operations, which he said were performing well.